I picked up a National A38 last week that is an original Mobil pump with ad glass, shield sign and also a set of these porcelain pricer signs. I think I have seen this type of pricer before but cant remember where. Does anyone have any information on what the pricer numbers look like that go in the signs? Are they metal, porcelain, or card stock? If someone has a bunch of them I would like to get a few to complete the look of the pump.